WATCH: Donald Trump Says ‘We Will Come Up With the Cures to Many, Many Problems, to Many, Many Diseases, Including Cancer and Others’

Joseph “Beau” Robinette Biden III died of cancer in May of 2015. As a result, his father, Joseph “Joe” Robinette Biden Jr., made reference to curing cancer in a public appearance in Iowa on June 11.

People understood the importance for the former Vice President in light of the death of his eldest son and namesake from brain cancer. The younger Biden had been the 44th Attorney General of Maryland and also served the United States Army as a Major in the Army Judge Advocate General’s Corps.

However Donald Trump Jr. found Biden’s vow to cure the illness that killed his son something to mock during President Donald Trump’s Orlando MAGA rally. Trump Jr. has served in his family’s businesses and once co-hosted a reality show with his father.

that’s about as low as you could go since Vice President Biden’s son died from brain cancer — these people have no morals, empathy, they are all cruel, heartless and will take us down completely if they are not gone soon

Don jr. talking about Joe Biden efforts to cure cancer reminded me of this classic Trump story about stiffing a kids cancer charity while pretending he was a big donor. Keep America Great by turfing the ass in the White House. https://t.co/escZ9mJeDC

#WednesdayWisdom@DonaldJTrumpJr Regarding your “speech” last night: Just how many family members do you have that have fought and lost a cancer battle? Your ignorant remarks about Biden’s wish to find a cure is pure evil. Shame on you and your big mouth.

And his idiot followers buy this, of course. Can’t “cure” cancer w/o research and that costs money; you’ve bankrupted the country. Landing on Mars. Priority? It all sounds good to the mindless, gullible, Trump-sheep.

He can promise to build a Dyson sphere ffs but we all know he can’t deliver on anything other than racist and misogynist policies to distract from his mental illness, dementia, and professional incompetence

People took exception to Donald Sr.’s boast coming on the heels of Donald Jr.’s mocking of Biden making a lesser vow.

Here’s Donald Trump Jr mocking Joe Biden last night for vowing to try to cure cancer … followed by President Trump promising hours later, at the same rally, to cure cancer, AIDS, and “lay the foundation” for a Mars landing — all in his second term pic.twitter.com/VjU5E5A4N1

While in FL, Trump accused President Obama of colluding with Russia, insisted steel has come back in a big way even as the WSJ was reporting two more plants will go idle & Don Jr. made a few jokes about Biden curing cancer before Trump got on stage & promised to do the same thing

Many took to Twitter and tagged both Donald Jr. and Sr. with a message about both the son’s mocking comment and the father’s boast.

Hey @DonaldJTrumpJr. America is going to cure cancer all by herself, when we vote you and your despicable POS father @realDonaldTrump out of office come November 2020. You’re a disease, and the American voter is the cure.

President Trump used the Orlando MAGA rally as a chance to officially kick off his 2020 presidential campaign. His announcement came on the heels of conservative leaning paper Orlando Sentinelendorsing “Not Donald Trump” in 2020 with a scathing editorial and Quinnipiac University’s latest Florida poll results showing Trump behind all the Democratic frontrunners.